Close to five years clean. My two cents
Been addicted since age twelve for about twelve years. Been clean for about five years now.
Here are some things that might be of use to you:
Yes, it's worth it. It will get a hell of a lot worse before it gets better, but it does eventually get better.
The secret to defeating addiction is actually a change in environment. You can take this as serious as you want and move to an entirely new city, as I've done. Or you can start small, like I also did, and sleep in a different room. Your surroundings have to change over time if you want to drop old habits.
Stop counting the days. You either quit or you don't. Be easy on yourself if you fall down, but every time you get back up you have to have the mindset that you're in it to quit completely.
You're not alone, don't give up. Everyone here is so young, and you have a lot of running room yet before you can say I've tried my best. Keep going.